I wanted to add another question to this as well.
What if, in an out patient(office in my case) where the physician is doing a planned major surgery, for example MOHS that includes the (major) adjacent tissue transfer CPT, but often the physician wants to do a separate skin exam and the additional diagnoses may be for something totally unrelated to the reason the patient is in for the (major) surgery, so the 57 really does not seem to be appropriate because the e/m was not the "decision for surgery" , it was an separate e/m, for something else, like an AK. I see this often, especially for mohs surgeons, doing additional services on a planned mohs session, (i.e., skin exam, adding on additional minor surgical services such as cryos, PDT's, same day) I would drop the e/m code if a minor surgery was added, but what about when the physician states in note they performed a skin exam or addressed another problem and there is other dx codes to append to e/m - but the e/m is not the decision for that surgery?